The conventional F-type wrench as shown in FIG. 17 and comprises a first part 61, a second part 62 and a pivot 63, wherein the first part 61 has a first pivotal portion 611 at the first end thereof and the first pivotal portion 611 has a first hole 612 transversely defined therethrough. The first part 61 has a ratchet gear pivotably connected thereto and the ratchet gear has a recess with a specific size. The second part 62 has a certain length so as to be held by the user, and a second pivotal portion 621 is connected to a first end thereof. The second pivotal portion 621 is a U-shaped portion and is pivotably connected to the first pivotal portion 611. The second pivotal portion 621 has a second hole 622 transversely defined therethrough which is located corresponding to the first hole 612. The second hole 622 has a threaded portion 623 therein. The pivot 63 extends through the first and second holes 612, 622 so that the first and second pars 61, 62 are pivotably connected to each other. Although the first and second pars 61, 62 are pivotable to each other, they cannot be separated from each other. Generally, the ratchet gear in the first part 61 has a specific size, and there are over thirty different sizes in the Metric system and the English system. If the manufacturers want to produce the wrenches to cover all of the different sizes, the number of the first and second parts 61, 62 will be significant, and this means the manufacturing cost is high. U.S. Pat. No. 7,036,403 discloses a wrench having the similar shortcoming.
The present invention intends to provide a wrench to improve the shortcomings mentioned above.